1. Collect data: Click Reset. Change the Half-life to 10 seconds and click Play. Select the TABLE tab and record the number of radioactive atoms at each given time below. 0 s: _128 10 s: _60 20 s: _32 30 s: 17 40 s: _6 50 s: _5

2. Analyze: What pattern, if any, do you see in your data?

Calculate the ratio of h+ ions to oh– ions at a ph = 7. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 7. are they the same? why or why not? record your comparison in table a. what is the concentration of h+ ions at a ph = 7? mol/l what is the concentration of oh– ions at a ph = 7? mol/l what is the ratio of h+ ions to oh– ions at a ph = 7? : 1